# Why work is dot product of force and displacement?

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## Why work is dot product of force and displacement?

My question : Why is work the dot product of force and displacement and not the cross product? Their answer : Because it is a scalar quantity and not a vector.

What is force and displacement?

In mechanics, it is frequently necessary to distinguish between the distance that a point moves—or through which a force acts—and the displacement of the point or the force. Displacement is a vector quantity because it has both magnitude and direction.

### What is the dot product of force and distance?

Under those conditions, work can be expressed as the product of the force acting on an object and the distance the object moves. The dot product essentially tells us how much of the force vector is applied in the direction of the motion vector.

What is the product of the force applied and the displacement made?

Work is the transfer of energy by a force acting on an object as it is displaced. The work W that a force F does on an object is the product of the magnitude F of the force, times the magnitude d of the displacement, times the cosine of the angle θ between them. In symbols, W = Fd cos θ.

#### Is work done a dot product of force and displacement?

Work done by a constant external force is equal to the dot product of external force and displacement. Note: The dot product of two vector quantities gives a scalar result. Thus, work is a scalar quantity.

Why is dot product used?

We use dot products to calculate work in the first place because we don’t care if a force is acting perpendicular to the end net displacement of that object. 3) In linear algebra, another field of math, dot products are central because they help us define length and angle in the first place.

## Why is dot product useful?

Why is work a scalar product?

Work is a scalar quantity because it is the dot product of two vectors (Force and displacement). Dot product of two vectors becomes scalar quantity. So, work done has only magnitude but not direction.

### What is the product of force and speed called?

Answer: Thus, at any instant, the rate of the work done by a force (measured in joules/second, or watts) is the scalar product of the force (a vector), and the velocity vector of the point of application. This scalar product of force and velocity is known as instantaneous power.

Why is the work done a dot product of force and displacement?

Hence work done is dot product of force and displacement. Work done is equal to product of magnitude of force and magnitude of displacement and cosine of angle between them . Another example is power is dot product of force and velocity.

#### How is work expressed in the dot product?

In Introduction to Applications of Integration on integration applications, we looked at a constant force and we assumed the force was applied in the direction of motion of the object. Under those conditions, work can be expressed as the product of the force acting on an object and the distance the object moves.

Is the dot product the same as the scalar product?

For this reason, the dot product is often called the scalar product. It may also be called the inner product. The calculation is the same if the vectors are written using standard unit vectors. We still have three components for each vector to substitute into the formula for the dot product:

## How to calculate the work done by a given force?

Find the direction cosines of a given vector. Explain what is meant by the vector projection of one vector onto another vector, and describe how to compute it. Calculate the work done by a given force. If we apply a force to an object so that the object moves, we say that work is done by the force.